1. Field of the Invention
The present invention relates to image processing apparatuses, and particularly to an image processing apparatus having a plurality of image processing blocks that are capable of real-time processing of an image signal inputted from outside.
2. Description of the Background Art
For an image input apparatus such as a digital still camera, Japanese Patent Application Laid-Open No. 2000-236473 discloses a conventional image processing apparatus including an imaging device, an analog signal processing circuit connected to the imaging device, and a Real-time Processing Unit (RPU) connected to the analog signal processing circuit, where the RPU is capable of processing in a real-time manner an image signal outputted from the analog signal processing circuit.
However, this conventional image processing apparatus does not offer sufficient versatility in the following points:
the number of taps of spatial filter in the spatial filtering block is fixed;
it is not possible to obtain a high-frequency component when the spatial filter is set not as a high-pass filter;
it is not possible to obtain a mixture signal, such as a signal containing center pixel signal and low-frequency component at a desired ratio, as an output signal from the spatial filter;
image quality is considerably deteriorated when a divergence occurs between a pixel as a source of generation of feature data for modulation and a pixel as a target of modulation of luminance signal;
image quality is considerably deteriorated when a divergence occurs between a pixel as a source of generation of feature data for modulation and a pixel as a target of modulation of color signal;
no means is provided which is capable of applying high-speed color transformation to 2-channel color signals (Cb, Cr) outputted from the color-space transformation block;
signals are processed as YCbCr color-space signals after the output of the color-space transformation block, and only a signal of the same color space can be obtained as the final output signal; and
signals are processed as 8-bit-system signals after the output of the gamma correction block, and only a signal of the same number of bits can be obtained as the final output signal.